Honda FCX Concept

Fuel cells will power
the cars of the future. We who follow the auto industry hear this quite often,
and the vehicles admittedly sometimes seem like a distant pipe dream. But if
Honda’s futuristic FCX Concept is any indication, the cars are a lot closer to
reality than many might think.

A
production version closely based on this FCX Concept, first shown on the
2005 auto show circuit, is already confirmed to be headed for limited production,
with the first deliveries occurring sometime in calendar year 2008. According
to Honda, the 2008 FCX “will be the most advanced and powerful hydrogen
fuel-cell passenger car on the planet.”

It’s not
officially certified for
U.S. roads, but the production
version to come in 2008 will very closely follow it, both mechanically and
cosmetically. Honda currently has only two completely finished and fully
functioning FCX Concepts, and as a gesture of their complete confidence in the
motoring press, both were brought out to
California’s
Monterey
Peninsula so that, within the confines of
Laguna Seca Raceway, we could be allowed some significant seat time behind the
wheel.

Fuel-cell
primer

But first, a little fuel-cell
primer: The governing concept behind a fuel-cell is that there are two electrode
layers separated by a thin proton exchange membrane, together called membrane
electrode assembly (MEA) layers. Hydrogen enters from one side, while oxygen
enters from the other. Oxygen from the air attracts the hydrogen’s protons, and
as the protons pass through the membrane, there are two results: 1) water is
formed, and 2) electrons are caught in the membrane and brought through a
circuit to create an electrical current. A fuel-cell stack combines hundreds of
these cells, basically serving as a giant battery pack comprised of hundreds of
cells in series.

To simplify even further in case
too many notes were being passed during your high-school physics class, a fuel
cell is a sort of battery that never needs to be recharged, just fueled with
hydrogen. And in such a vehicle, the fuel-cell stacks provide electricity to
power what’s essentially otherwise an electric car.

Honda has moved very quickly to
not only develop a practical fuel-cell vehicle but also to develop the fuel-cell
stacks that power it. The automaker was a latecomer to fuel-cell vehicle
development (it been researching fuel cells since the late ’80s but didn’t start
its vehicle project until 1998, when Daimler-Benz and Toyota already had working
models). On an early version of its FCX Honda used its own
meticulously assembled fuel-cell stack but later opted to temporarily use a
Ballard Power Systems unit that, at the time, offered weight and packaging
advantages.

“We were still using a Ballard
stack in 2002 when we simultaneously delivered vehicles to market in the
U.S. and
Japan ,” said
Sachito Fujimoto, the FCX’s senior chief engineer.

Shortly thereafter, in 2003, Honda
engineers overcame some of the design hurdles with its second-generation
fuel-cell stack. Though less than half the size and weight of the previous
stack, the second-gen unit produced significantly more power, more reliably
because of a unitized seal system replacing separate
seals.

Gravity on its
side

There have been a few tweaks over
the past few years to that design, but — again, aside from the car itself — the
completely new, third-generation fuel-cell stack is big news. The so-called V
Flow FC Stack is a major design departure, with the membrane electrode assembly
(MEA) layers aligned vertically, rather than horizontally as in previous
versions of Honda’s own fuel-cell stack and the Ballard-supplied one that
preceded it. The V Flow unit also goes to a so-called vertebral layout — where
all of the systems are aligned along a center tunnel that goes through the
stack.

Glory Days cover

Thanks to design advancements, the
whole stack now has the dimensions of a small suitcase. Its volume is down to 52
liters, from 66 liters, while the arrangement boasts improved water drainage
(thanks to gravity) and a significant improvement in cold-weather startup
performance (down to –20 degrees C). The improved water drainage aids cold
starts, and heat mass is significantly reduced, so warm up takes a quarter of
the time than with the previous stack. Most importantly, the new stack produces
100 kW — 50 percent more power by volume and 67 percent more power by weight
compared to the second-generation stack currently used on the current,
limited-production FCX.